CVE-2021-32715Published

hyper is an HTTP library for rust. hyper's HTTP/1 server code had a flaw that incorrectly parses and accepts requests with a `Content-Length` header with a prefixed plus sign, when it should have been rejected as illegal. This combined with…

Exact source revision recorded 24 Oct 2026 18:17:28 UTC. It does not establish the source's current position. Latest evidence.

Recorded JSON

nvd · CVE-2021-32715

Published

hyper is an HTTP library for rust. hyper's HTTP/1 server code had a flaw that incorrectly parses and accepts requests with a `Content-Length` header with a prefixed plus sign, when it should have been rejected as illegal. This combined with an upstream HTTP proxy that doesn't parse such `Content-Length` headers, but forwards them, can result in "request smuggling" or "desync attacks". The flaw exists in all prior versions of hyper prior to 0.14.10, if built with `rustc` v1.5.0 or newer. The vulnerability is patched in hyper version 0.14.10. Two workarounds exist: One may reject requests manually that contain a plus sign prefix in the `Content-Length` header or ensure any upstream proxy handles `Content-Length` headers with a plus sign prefix.

NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.

Source analysis status: Modified

Weakness classifications: CWE-444

Original publisher date fields

published: 2021-07-07T20:15:08.750

lastModified: 2026-06-17T03:53:29.050

1 source CPE criteria · context only

cpe:2.3:a:hyper:hyper:*:*:*:*:*:rust:*:*

The original JSON retains the logical configuration operators, exclusions and version bounds.

Source published: 7 Jul 2021 20:15:08 UTC
Source modified: 17 Jun 2026 03:53:29 UTC
Observed here: 24 Oct 2026 18:17:28 UTC
Source terms: NIST NVD usage terms; underlying source attribution retained

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · [email protected] · Secondary · 3.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N

CVSS 3.1 · [email protected] · Primary · 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

CVSS 2.0 · [email protected] · Primary · 4.3 AV:N/AC:M/Au:N/C:N/I:P/A:N